Apparatus for severing the root system of the tree from the trunk during the tree-felling operation

ABSTRACT

An apparatus for severing the root system of a tree from the tree trunk during tree-felling comprising a gripping part, in operation being clamped to the trunk, and a cutting part for cutting of the roots. The cutting part includes a circular knife of interconnected knives arranged to encompass the trunk, and the cutting part is displaceable relative to the gripping part for cutting the roots, usually while pulling or pushing the tree upwards out of the ground in which part of the root system remains. Jacks or other power mechanism is used for moving the cutting part away from the gripping part fixed to the trunk. Timber is saved since no stump remains.

United States Patent 1 Wiklund et a1.

[75] Inventors: Per Martin Wiklund, Taby; Johan Ingemar Palm, Osterskar,both of Sweden [73] Assignee: Ostbergs Fabriks AB, Alfta, Sweden [22]Filed: Dec. 3, 1970 [21] Appl. No.: 94,731

[52] US. Cl 144/34 R, 144/309 AC [51] Int. Cl A0lg 23/08 [58] Field ofSearch 144/2 N, 2 Z, 3 D,

144/34 R, 34 A-34 E, 309 AC [56] References Cited UNITED STATES PATENTS10/1970 Sutherland; 144/309 AC 7/1971 Landers 144/2 Z Bombardier 144/2 ZJorgensen 144/2 Z Primary ExaminerGerald A-. Dost AttorneyYoung &Thompson 57 ABSTRACT An apparatus for severing the root system of a treefrom the tree trunk during tree-felling comprising a gripping part, inoperation being clamped to the trunk, and a cutting part for cutting ofthe roots. The cutting part includes a circular knife of interconnectedknives arranged to encompass the trunk, and the cutting part isdisplaceable relative to the gripping part for cutting the roots,usually while pulling or pushing the tree up wards out of the ground inwhich part of the root system remains. Jacks or other power mechanism isused for moving the cutting part away from the gripping part fixed tothe trunk. Timber is saved since no stump remains.

2,535,099 12/1950 Slick 214/3 2 Claims, 5 Drawing Figures 24 I 26 23 n o22 2 260 T v I I /7 2002 uh-5 PATENIED JUN 1 2 I973 same or 4 FIG. 2

PATENTED JUN l 2 I973 snasra 0f 4 IN V EN TORS Pee Mner/A/ WM; (/1160APPARATUS FOR SEVERING THE ROOT SYSTEM OF THE TREE FROMTHE TRUNK DURINGTHE TREE-FELLING OPERATION The present invention relates to an apparatusfor severing the root system of the tree from the tree trunk during thetree-felling operation. The apparatus comprises a gripping part which isdesigned to be clamped to the tree trunk and a cutting part arranged tocut off roots. The apparatus is primarily intended to be mounted, e.g.on a crane arm of a tractor, or in a treefelling machine or processor.

The main object of the invention is to make the apparatus so that it canrecover the useful timber in the trunk extension down at and under theground level, without having to pull the entire root system of the treeout of the ground.

The invention is mainly characterized in that the cutting part includesone or more cutting tools, in operative position mainly encompassing thetrunk, the cutting part being displaceable, relative to the grippingpart, along the trunk while the cutting tool(s) are kept in the positionencompassing said trunk so that the roots are cut off by thisdisplacement and in the extension of the trunk there remains a usable,increased end part of the trunk as merchantable timber.

The cutting part can be provided with or form a ground support which,during the extension of the cutting part along the trunk, rests on theground, whereby continued extension of the cutting part with the grippart fixed to the trunk causes a thrust that lifts or tends to lift thetrunk. Because of its shape, the cutting part, as such, can meet suchstrong resistance when pressed against the trunk encompassed ground thatthe tree is pulled out of the ground at the same time as the side rootsare cut off. In this case, special ground support is dispensed with. Forthe movement of the trunk relative to the cutting part, it is possibleto use a power mechanism having lifting means which rest on the groundand function to lift the tree or trunk during the operating of thecutting device. Alternatively, a power mechanism can operate between thegripping and cutting parts so that it can move the gripping and cuttingparts away from each other after the gripping part has been clamped tothe trunk. Said power mechanism produces the desired relative movementbetween the trunk and the cutting part.

The cutting part can be shaped as a closed ring or sleeve with one endedge shaped as a cutting edge. However, easier use is achieved if it isshaped like an open sleeve consisting, in principle, of two pivotedhalves. Each half may consist of several cutting tools which form linksin a cutting system. The cutting systems are preferably attached on armswhich are movable during use towards and away from the trunk. In thisway, the knife systems are brought by these arms to together encompassthe tree trunk. A stretching device can communicate with the knifesystems so that it can tighten said systems around the tree trunk.

Further characteristics of the invention are evident from the followingdescription of an unit shown on the enclosed drawings. This unitconstitutes an example of the applicability of the invention. FIG. 1schematically shows the arrangement of the unit mounted on a crane arm;FIG. 2 shows a side view, partly in vertical section, of essential partsof the unit; FIG. 3 is a horizontal view substantially along the lineIIIIII in FIG. 2, FIG. 3a is a vertical section of a component in FIG. 3along the line III a III a in FIG. 3, and FIG. 4 is a horizontal view ofthe gripping part, substantially along the line IV IV in FIG. 2.

The unit comprises two main parts: a gripping part 1 and a cutting part2. These parts are held together by one or more hydraulic cylinder units3. The cutting part is placed at a lower level than the gripping part 1and can be moved in relation to the gripping part 1 by means of thehydraulic cylinder unit 3.

The parts 1 and 2 are mounted as a unit on a crane arm which is movablysupported by a tractor 16 or the like, for example pivotally on a craneshaft 17 on the tractor. The crane arm consists of a lifting arm 18pivotally journalled in the crane shaft 17 in the vertical plane andflexibly connected to a lever arm 19. A hydraulic lifting cylinder 21may be used to adjust the height of the lifting arm 18 and for thispurpose cooperates with an attachment 23 on the arm, by means of itspiston rod 22. Similarly, the lever arm 19 is vertically adjustable bymeans of a hydraulic rocker cylinder 24 flexibly connected to theattachment 23 and an attachment 25 on the lever arm. The lever arm 19also flexi bly carries a hydraulic, so-called tilt cylinder 26 whosepiston rod 26a is flexibly connected to the lever arm 19 by means of alink 27 and by means of another link 42 to an attachment member 20joined flexibly to the lever arm 19 about a peg 20a. This attachmentmember 20 belongs to the gripping part which will be described later.

The gripping part 1 comprises hydraulically operated gripping arms 4a,4b, 40, which grip the tree T and press it against a rear support 4d.The gripping arms 4a, 4b, 4c and the support 4d should have largecontact surfaces or clamping plates against the surface of the tree sothat considerable force may be exerted without the surface pressurebeing so great that the timber is crushed. The contact surfaces shouldalso possibly be provided with horizontal ribs or the like to preventthe tree T from sliding axially in the gripping part.

The gripping arms 4a and 4b are placed at the top and bottom of thegripping part in approximately the same vertical plane and the grippingarm 40 at a level between these, whereas the support 4d is placed on theopposite side of the tree (see also FIG. 4). The curve distance betweenthe gripping arms 4a, 4c and the support 4d is preferably about Thegripping arms 40, 4b, 4c are pivotally journalled about vertical shafts34 so that they can be clamped against the tree T with the desiredpressure by the action of hydraulic cylinders 32a, 32b which areflexibly joined to respective gripping arms 4a, 4b by piston-rodprojections 33a, 33b. Clamping plates 5a, 5b, 50 at the ends of thegripping arms 4a, 4b and 4c, respectively, can thus be pressed againstthe surface of the tree T and adapted according to the thickness of thetree. FIG. 4 shows at T 1, that even a narrow tree trunk can be clamped.The support 4d with its clamping plate 5 is stationary and thus servesas abutment.

The hydraulic cylinder unit 3 comprises three hydraulic cylinders 3, 3ain the embodiment shown. The former has greater cross sectional surfacethan the latter two cylinders 3a. One of the weaker cylinders 3a isjoined by means of its piston rod 13 and piston rod projection 14 withpeg 15, to a yoke 12. This yoke is joined to arms 8a, 8b by means ofpegs 10a, 10b and attachments 9a, 9b, similar to piston rod projections,the arms 80, 8b being attached to the pressure plates 5a and 5b.

In this way, lifting force from one of the weak hydraulic cylinders 3ais transmitted through the yoke 12 to the clamping plates 5a, 512. Atthe same time, a force is transmitted from the other weak hydrauliccylinder 3:: via piston rod projection 9c, peg 10c and arms 8c to theclamping plate 5c. The forces from the gripping arms 44:, 4b and 4c aretransmitted to the pressure plates 5a, 5b, and 5c via the balljoints 6a,6b and 6c. The stronger hydraulic cylinder 3 transmits its force to theattachment 35 through a piston rod projection 36a and a peg 36b. Theattachment 35 is rigidly attached to the construction formed by theplates 35a, 35b and the tubes 35c and 35d. The tubes 35c, 35d, 10 and 1fform, together with the plates 35a, 35b, 1a, 1b, 1c and 1d, the frame ofthe gripping part.

The force to the gripping arm 40 is transmitted from the cylinders 32aand 32b through the shaft 31 which is flexibly connected to the cylinder32a and the cylinder attachment of the cylinder 32b and the gripping arm40. All of the three cylinders 3 and 3a are flexibly connected at theirlower ends to the attachment 30 on a support plate 2a of the underlyingcutting part 2. Thus, when the hydraulic cylinders 3, 3a are fed withpressure liquid, the cutting part 2 has a tendency to move downwardlyand the gripping part 1 upwardly.

The cutting part 2 includes arms 46 and 47 pivotable about shaft pins 48and 49, respectively. The swinging movement is effected with the help ofhydraulic cylinders 50 and 51 arranged between attachments 52 and 53,respectively, on a movable carriage 54 and the attachments 55 and 56 onthe arms 46 and 47, respectively. The carriage 54 moves in guides 57and] 58 and can be displaced forwards and backwards by hydrauliccylinders 59 and 60 which on one side are flexibly connected toattachments 59a, 60a on the support plate 2a and on the other side bymeans of their piston rods, to attachments 59b, 60b on the carriage 54.

In the gripping arms 46 and 47, respectively, are two knife systems 61and 62, respectively, each consisting of links pivoted in relation toeach other and having a cutting edge 63 facing down. The knife systemsare attached at one end in end links 64 and 65, respectively, which aresecurely attached to the arms 46 and 47, respectively on the partsfacing away from each other. At the other end the knife systems areflexibly connected to an attachment link 66 which is displaceable in thehorizontal plane along the center plane 2b of the cutting part 2. Thismovement takes place in relation to the carriage 54 by means of ahydraulic cylinder 68 and its piston rod 68a in order to tauten theknife system 61 and 62 and thus ensure that the knife systems caneffectively surround trees of varying diameter. A stationary,single-curved knife 67 with lower cutting edge 63 acts as abutment forthe tree and also enables the tree to be completely surrounded by knifeelements provided with cutting edges.

The cutting part is also provided with a suitable sawing or cuttingdevice, shown here in the form of a socalled swinging bar with a sawchain 71 driven by a motor 70 suitably geared. This chain 71 runs over achain wheel 70c and a chain wheel 70a driven by the motor, attached on apivoting arm 70b, which is actuated by the piston rod 69a of a hydrauliccylinder 69 which is flexibly connected to an attachment 69b on thesupport plate 2a. The saw chain 71 can be moved towards the tree withthe desired force, when actuated by the hydraulic cylinder 69.

The unit consisting of parts 1 and 2 is pivotable about a horizontal peg41 (FIG. 2) so that said unit can be adjusted according to the slant ofthe tree. After adjustment, this turning movement is retarded by meansof a braking device described below. The peg 41 is fixed in the frame(la) of the gripping part 1 and supports a braking disc 39 which cancooperate with brake blocks 38 pivotably placed about pegs 40a on arms37 which in turn are pivotable about a peg 40 and can be operated bymeans of a piston rod belonging to a hydraulic cylinder 37a and having apiston rod projection 37b to press the brake blocks 38 against the brakedisc 39 or release them from this, respectively. The brake should bereleased and thus release the peg 41 when the units 1, 2 are required tobe able to turn when the tree is gripped, and when it is released if theunit supporting the combination of parts 1 and 2 is sloping on its base.The peg 41 is journalled in a box 45 which is attached to the attachmentmember 20 provided with reinforcing flanges 44 and joined to the leverarm 19 through the peg 20a.

The felling unit operates in the following way:

The unit with the gripping arms 40, 4b, 4c of the gripping part open andthe cylinders 3, 3a, 50, 51, 59, in withdrawn position and the cylinder68 in extended position, is placed so that the tree is between thegripping arms 4a, 4b, 4c of the gripping part 1 and the arms 46 and 47of the cutting part 2. When the tree is to be felled, the cutting part 2shall be at such a level that the root swelling on the tree trunk doesnot make the trunk so conical that further transport, etc. of the timberis made difficult. The tree is then gripped, by the closing of thegripping arms 4a, 4b and 4c in the gripping part 1 and the arms 46 and47 in the cutting part2. Immediately after this, the carriage 54 ismoved back until the links 64 and 65 and the knife 67 come into contactwith the outer surface of the tree and the attachment link 66 is drawnback with the help of the cylinder 68 until the knife systems 61 and 62are stretched and in abutment with the surface of the trunk.

Alternatively, the tree may first be encompassed by the cutting part 2only, after which the entire unit is lowered as far as possible and thegripping arms 4a, 4b, 4c in the gripping part are closed.

The cylinders 3, 3a are then projected synchronously so that the cuttingpart 2 is pressed downwardly and the knife systems 61 and 62 with thecutting edges 63 (also on the knife 67) cut away the root swelling onthe tree, and possibly also some of the side roots. When the cuttingunit 2 has been moved towards the ground, the cylinders 3, 3a willgradually exert a contact pressure between the cutting part 2 and theground on the one hand and the upwardly directed force against thegripping part 1 will be so great that the tree is pulled up out of theground and its side roots will be cut off by the knife systems. Thecrane arms 18, 19 or a separate crane may possibly also assist with thelifting. When the unit operator judges that all the merchantable timberis above the horizontal plane where the pivotable bar, formed by thechain saw 71, is located, remaining roots are sawed off by the saw 71which receives its feeding motion from the cylinder 69.

The felled tree is then handled in the grip of the gripping part 1whereas most of the roots remain in the ground.

said cutting part and said gripping part away from each other along thetrunk in the gripping position thereof while said ground support restson the ground to force said knife edges through the root system of thetree, thereby to produce an increased end part of the trunk asmerchantable timber in the root extension of the trunk.

2. Apparatus as claimed in claim 1. and a cutting device that movescrossways to the tree trunk to cut off roots entrained by the tree trunkduring the lifting of said trunk.

1. Apparatus for severing the root system of a tree from the trunkthereof, comprising a gripping part for clamping the tree trunk, acutting part displaceable below and relative to said gripping part, saidcutting part including a knife edge directed downward away from saidgripping part, and said cutting part also including a ground support,and power means to move said cutting part and said gripping part awayfrom each other along the trunk in the gripping position thereof whilesaid ground support rests on the ground to force said knife edgesthrough the root system of the tree, thereby to produce an increased endpart of the trunk as merchantable timber in the root extension of thetrunk.
 2. Apparatus as claimed in claim
 1. and a cutting device thatmoves crossways to the tree trunk to cut off roots entrained by the treetrunk during the lifting of said trunk.